110 A Synopsis of the Recent British Ostracoda. 



excretions, with, the exception of the milt of the male and the 

 roe of the female being of an exhausting kind. 



The conclusion, then, at which I think we may safely arrive 

 with regard to the food of the salmon is — that it feeds freely in 

 the sea, and chiefly on other kinds of fish, such as sand- 

 launces, herrings, and other clujoeidee, though other animals, 

 such as shrimps, and various Crustacea occasionally form part 

 of its diet ; that during its sojourn in the sea the salmon lays 

 up a store of adipose matter ; that it very seldom feeds during 

 its abode in the fresh-water rivers, but lives on the supplies of 

 its own internal fat ; that though for some time the flesh does 

 not perceptibly deteriorate, it is rendered poorer in quality 

 towards the eaW. of its sojourn in the fresh water, both from 

 the exhaustion of its own supplies of fat and from the effects 

 of spawning -, that it rapidly improves when it has reached the 

 salt water, when it again lays up a fresh supply of adipose 

 matter, which will support it during its sojourn in the rivers. 



A SYNOPSIS OF THE RECENT BRITISH OSTRACODA. 



BY GEOEGE STEWAEDSOH BEADY, M.E.C.S., C.M.Z.S., 



Secretary to the Tyneside Naturalist's Field Club. 



{With Two Plate.) 



Of the various orders included in the great tribe Entomostraca, 

 there is, perhaps, not one more generally interesting than that 

 of which we propose to treat in the present paper. When we 

 consider the great abundance and wide dispersion of the 

 Ostracoda through the fresh waters and seas of our own 

 period, and the countless myriads in which the shells of ante- 

 diluvian species have come down to us, embedded in strata of 

 varied character and age — for example, Silurian, Liassic, Car- 

 boniferous, Permian, Tertiary, and Post-tertiary — it will be 

 evident that the geologist and paleontologist must, to a very 

 large extent, share their interest in this group with the student 

 of recent zoology and physiology. It will be seen also that 

 any light which may be thrown upon the structure and habits 

 of living forms must likewise be of great importance to the 

 student of extinct species, as tending to exhibit more clearly 

 their natural affinities, and to establish sounder principles of 

 classification than can be attained by the study merely of the 

 external covering of the animal, which only is left to us in the 

 case of fossil examples. The prodigious numbers in which the 

 fossilized carapaces of these creatures sometimes occur, is 



